The present invention relates to a torque responsive control device for providing a fluid control that is proportional to the torque output of a primary mover such as a motor.
In the field of the present invention, it is known to provide a continuous pressure monitor for a fluid that is being employed in a hydraulic system for controlling the operation of a machine element. For example, hydraulic systems responsive to torque are known which vary the position of blade elements in turbines or the like. In addition, a number of devices are known which measure the torque in a shaft which may either be rotating or static and which are used to control elements such as the pitch angles of propellers in ships, planes, or other devices. However, these devices are generally complex in terms of their structure and operation and thus are costly to manufacture and install in such equipment. Also, it has been the practice to manufacture and design torque monitoring devices for relatively specific applications thereby rendering many of the devices of the prior art useful in only such specific environments.
The torque monitoring device of the present invention has for its principal object the provision of a substantially less complex yet highly reliable apparatus that can be easily incorporated into a number of motor drive systems and yet will be substantially less expensive to manufacture than the previously known devices in this field.
In a preferred embodiment, the apparatus includes a drive shaft which may be directly coupled to the output of a primary motive source, a driven shaft and a coupling means for transmitting torque from the drive shaft to the driven shaft. The coupling means is mounted in a cylindrical housing through which fluid is pumped and the characteristics of which are to be controlled. To this end, the coupling means is slidingly mounted in the housing on one end of the driven shaft and includes a torque responsive means engaged with the drive shaft so that, as the drive shaft rotates, the torque responsive means will cause movement of the coupling means to vary a characteristic of the fluid being pumped through the housing. In a preferred embodiment, the coupling means is employed to control an opening through which the fluid passes so that as the torque of the drive shaft increases, the pressure of the fluid will vary in response to movement of the coupling means. The increase or decrease in pressure, whichever is more convenient to employ, is then utilized in an hydraulic control system to effect the desired mechanical movement. As one example, the variation in the fluid pressure may be employed to control a continuously variable transmission in an automotive vehicle whereby the torque transmitted to the drive wheels of the vehicle can be maintained at an ideal ratio to the torque output of the motor to result in a conservation of fuel.
The foregoing and other advantages of the present invention will become apparent as consideration is given to the following detailed description taken in conjunction with the accompanying drawings, in which: